The recent discovery of a novel species of Leishmania infecting marsupials in the Australian Northern Territory, namely, Leishmania australiensis, has raised many questions and concerns, including the risk of human leishmaniasis becoming endemic in Australia. Although L. australiensis is considered to be non-pathogenic to humans, it has high degree of similarity to human pathogenic species, which makes it an ideal candidate for identifying mechanisms of pathogenicity and virulence in human leishmaniasis. Previous work done in our laboratory has showed that L. australiensis is able to infect and survive as amastigotes in a variety of human and murine in vitro cells, including macrophages, neutrophils and dendritic cells. In addition, this parasite appears to modulate such cells and is resistant to complement mediated killing. In this study we show the effects of in vivo infection using BALB/c nu/nu mice as models. The subjects were infected with 105 stationary phase L. australiensis promastigotes in the ear pinna and examined weekly for skin lesions. The serum monitored for the presence of antibodies and cytokines and post mortem analysis of infected tissue as well as draining lymph node. The increased susceptibility of nude mouse to Leishmania infections in general will provide an ideal initial mouse model to study L. australiensis, analyse the infection in the absence of T cell lymphocytes and more importantly, compare to human pathogenic Leishmania species. The relevance of such a study is not limited to clarifying the pathogenicity of human pathogenic species but, as shown recently with L. tarentolae, non-human pathogenic Leishmania species may represent a safe alternative to either attenuated or subunit vaccines.
|Title of host publication||Fifth World Congress on Leishmaniasis (WorldLeish 5)|
|Publication status||Published - 2013|